Compound stencil-sheet



(Specimens.)

'T. H.STAGKHOUSE. COMPOUND STENCIL SHEET.

No. 565,043. Patented Aug. 4, 1896.

wsTNEs E 2 \NVENTOR s 8 Jr. JMM

r anms mans ca. H- maumo. wuummon, n. c,

UNITED STATES PATENT FFICEQ THOMAS H. STAOKIIOUSE, OF PHILADELPHIA, PENNSYLVANIA.

COMPOUND STENCIL-SHEET.

SPECIFICATION forming part of Letters Patent No. 565,043, dated August 4, 1896.

Applioaticu filed October 5, 1895. Serial No. 564,710, (SpecimensJ To aZZ whom, it HMLZ/ concern:

Be it known that I, THOMAS H. STACK- HOUSE, a citizen of the United States, and a resident of the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in StencilSheets, of which the following is a specifica-tion.

My invention relates to improvements in stencil-sheets, and more particularly to improvements in that class of stencil-sheets which are adapted to be out upon a typewriting machine; and the object of my invention is to furnish a compound stencil-sheet, the tensile strength of which will be much greater than that of any stencil-sheets heretofore made, and from which a much greater number of impressions or copies can be made than has heretofore been possible.

The base of my stencil-sheet is formed of a sheet of fibrous paper of a thin, open texture, preferably of the paper known as J apanese dental ,or yoshino paper, which is treated with wax in the usual and well-known manner for producing stencil-sheets. Upon one or both sides of the base-sheet, I place a sheet of thin, close-grained paper, preferably a highly-calendered tissue-paper containing sizing, which is also preferably waxed or oiled, so as to make it impervious toink. The latter sheet or sheets of paper may be secured to the base-sheet by pressure between rolls which maybe either cold or hot, or by means of a hot iron passed over the sheets after they have been placed on top of one another. If heated rolls or irons be used,the close-grained paper need not be waxed, as these irons or rolls would cause the wax on the base-sheet to melt, which would then be absorbed in sufficient quantity by the unwanted sheet or sheets to make them impervious to ink or moisture.

The stencil is formed or out upon the sheet in the usual and wellknown manner by a type-writing machine or other instrument. The close-grained paper upon being struck by the type or other instrument is at that point wholly or partially destroyed or cut through, while the fibers of the base-sheet, being exceedingly tough and strong, suffer little or no injury, but the wax which they hold is, where the type strike, shattered and pushed aside orotherwise removed, permitting the free passage of ink at these points.

The use of the thin, close-grained paper in connection with the base-sheet of open fibrous texture permits the use of a much harder war, that is, one of a higher melting-point, than is possible where the base-sheet alone is used, the advantages of which in warm weather will be obvious.

In the accompanying drawings, Figure 1 shows my improved stencil-sheet formed of a base-sheet, one side of which carries a sheet of the close-grained calendered paper; and Fig. 2, a stencil-sheet formed of a base-sheet placed between two sheets of close-grained calendered paper, A being the base-sheet and B the covering-sheets.

In cutting the stencil the coveringsheet B preferably receives the blow of the type, if the porous sheet is coated upon but one side with paper.

The wax used for coating the porous paper maybe that generally employed for this purpose, which is composed largely of paraifin, although any suitable material impervious to ink may be used.

The commercial type-writer stencil-paper now in general use is made by coating J apanese dental or yoshino paper with a soft wax, largely paraffin. Such stencil-paper is very frail and delicate, and is so much influenced by heat as to be of little value in warm or even in temperate climates, where the temperature ranges beyond 90 Fahrenheit. In fact, to such an extent is such stencil-paper influenced by heat that in many cases only a few good copies can be obtained from a stencil in warm weather.

In my stencil-sheet not only can loss was: be used, but the meltin g-point of the wax may be much higher than is possible with the stencil-sheets now in use.

I do not confine myself to the use of Japanese dental or yoshino paper, as any-porous paper maybe used as a base for my compound stencil-sheet.

I have found in practice that for a stencilsheet for use in the ordinary commercial typewriter better results are obtained by coating the basesheet on but one side with paper, although, if a very large number of copies are required, the base-sheet should have both sides coated with paper. In the latter case it generally requires somewhat more pressure to perforate the stencil-sheet.

I have also found in practice that better results are obtained by coating the porous sheet with Wax in a similar manner to that used in making the ordinary commercial stencilsheets, and then affixing the paper coating to the said porous sheet with roll-pressure with just sufficient heat to cause the tissue-paper coating'to adhere firmly to the said porous waxed sheet. 1

As a paper coating for the waxed porous sheet I prefer to use a thin, close-texture, well-calendered tissue-paper, containing 0011- siderable sizing. I do not confine myself to a highly-calendered tissue-paper, for a paper of slightly-open texture may be used to good advantage, although I much prefer an exceedingly close texture highly calendered tissue. I have used verythin Japanese tissue, giving good results, but there are several grades of tissue-papers which can be had in the market which give satisfactory results. I prefer to use anoiled tissue-paper, or a papersaturated with oil or coated lightly with wax, unlesssufficient heat is used when forcing the sheetsv together to causethe wax coating of the porous sheet to impregnate the tissuesheet.

The paper coating of the porous "waxed sheet should be sufficiently delicate or brittle to be readily broken or destroyed b ythe blow ofthe types. Of course, in some cases the tissue would not be wholly destroyed, although sufliciently so-to show an almost completely-broken line.

While I prefer to make my compound sten-. oil-sheet in themanner above described, if desired both the porous-sheet and the tissue sheet could be waxed or coated with a material impervious to ink at thesame operation.- The'art of waxing paper is well known and need not be described.

The art of producing'stencils is also well known, and does not need description.

A stencil-sheet prepared in the manner indicated may be used for the-so-called 'autographic process, and the same can be perfo-- rated not only with the wheel-pen, but also with a-stylus upon a roughened. plate.

A stencil-sheet prepared by my process possesses great tensile strength, vislvery durable, and will reproduce the maximum number of copies from one stencil.

I claim 1. A compound stencil-sheet, consisting of a sheet of thin, open, fibrous paper, and a 'a sheet of thin, open, fibrous paper, such as Japanese yoshino paper, filled or coated with a substance impervious to ink, as paraffin, and a sheet or sheets of close-grained, thin paper placed upon one or both sides of said first sheet, and secured thereto by heat and pressure.

4. A compound stencil-sheet,consisting of -a-sheet of thin, open fibrous. paper,-as Japanese yoshino' paper, filled or coated with a 1 substance impervious to ink, as parafiin, and a sheet or sheets of a close-grained, thin paper coated or filled with a substance impervious to ink, as paraffin or oil, placed upon 1 one or both sides of said first sheet, and secured thereto by pressure.

5. A prepared compound sheet for-use as a r stencil-sheet, consisting of two or more sheets. i one of which is ofan open, porous material, 1 the other of close texture, one or more. of said sheets being coated with a material'impervious to ink.

6. A prepared compound stencil-sheet consisting of two or more. sheets of paper at least one of which is of an open porous nature, and one or more of said sheets being coated or impregnated with a material impervious to ink.

7. As a new article of manufacture, a prepared compound sheet-for use as a stencilsheet, consistingx'of two or more sheets, one of which is of an open'porous materiahthe other of a thin, close texture, one or more of said sheets beingcoa-ted or impregnated with a material impervious to ink, substantially as set forth.

' 8. Asa newarticle'of manufacture, a sheet for use as a stencil-sheet, formed of two or more sheets, one or more of saidsheets being of an ope-n porous nature and one or more of said sheets being coated or impregnated with a substance impervious. to ink.

THOMAS H. STAOKHOUSE.

Witnesses:

HORACE D. REEVE, CHARLES A. BUTTER. 

